Other studies have found a relationship between frailty and OA measured with subjective criteria [ 15, 21].
However, the trained counselors who will conduct the telephone follow-up interviews will be different from the ones who completed the first interview and will not know the aim of the subjects; they will therefore be able to record outcome measures with minimal subjective bias.
Some environmental parameters were measured together with subjective investigation, and totally 1747 valid questionnaires were collected.
Only rarely have objective measures been correlated with subjective observer agreement.
While fatigue is a subjective experience, the presence of high amounts of variability between and within participants' fatigue, over even a short time frame of a day, argue the benefit of pairing objective measures of fatigue with subjective questionnaires.
Acceptance of the systems was measured with a subjective nine-item scale to measure specific acceptance in two dimensions; a usability dimension and a comfort dimension ([14]), while after the participants completed the experiment, a second, general usability scale measure was acquired.
We also found that although cognitive traits measured with the subjective numeracy scale (Fagerlin et al., 2007b) and the Cognitive Reflection Test (Frederick, 2005) correlated with judgments on food safety, the judgments were improved with the use of visual aids regardless of cognitive traits.
Fatigue is measured with the "Subjective Fatigue" subscale of the Checklist Individual Strength (CIS) [ 44].
In stress-induction studies, stress response optimally is measured with both subjective and objective indices because together these provide the strongest evidence for the internal validity of the stressor.
It also seems important to combine objective measures (e.g., adherence to clinical guidelines) with subjective measures such as patient satisfaction and continuity of care [ 38].
